138 C. E. Moss, W. M. Rankin and A. G. Tansley. 
east Devon, ashwoods occur on the calcareous soils of the Chalk 
and Upper Greensand. 
The area of natural or semi-natural beechwoods appears to 
have a western extension on the Inferior Oolite of the Cotswolds, 
but for the most part it does not extend north-westward of the 
Chalk escarpment. 
(A). Ash-oakwood association. This association is allied 
to that of the damp oakwood, into which it sometimes passes 
imperceptibly, thus forming a link between the two chief woodland 
series (see Scheme, p. 149). It occurs on highly calcareous clays, 
such as the Boulder clay of Cambridgeshire and neighbouring 
counties, on the Jurassic marls of Somerset, on the highly calcareous 
Upper Greensand of Hants, Dorset and East Devon, on some of 
the Silurian limestones of Herefordshire and district, on the deeper- 
soiled tracts of Mountain or Carboniferous Limestone, and on the 
calcareous glacial drift of the southern fringe of the Lake District. 
The ash and the oak share dominance in these woods so far 
as they are not coppiced, and the two are present in very various 
proportions in different woods. While Quercus Robur is the only 
oak in woods of this type on the calcareous marls and clays of the 
south, Q. sessiliflora, either alone or mixed with a varying amount 
of Q. Robur, is the oak of the woods referred to on the Silurian and 
Carboniferous Limestones. 
The general ecological conditions are in many ways the same 
as those of the damp oakwood, and the vegetation appears, on a 
preliminary inspection, to be identical. But the ash-oakwood 
possesses in abundance a number of species characteristic of 
calcareous soils, which are either only occasional in, or are quite 
absent from the damp oakwood. It is true of the ash series 
generally that the woods have a greater richness of flora ; and while 
in the case of the woods of the oak and birch series, the great bulk 
of the vegetation is made up of comparatively few species, in those 
of the ash series it is composed of a much greater variety. Thus 
among shrubs, the wayfaring tree ( Viburnum Lantana), the spindle- 
tree ( Euonymus europccus), and the climbing traveller’s joy ( Clematis 
Vitalba) are common, while they are very rare in oak woods. Such 
species as the dogwood ( Cornus sanguined), the privet ( Ligustrnm 
vulgare), the maple (Acer campestre), and even the sloe ( Primus 
spiuosa) and the hawthorn (Cratcegus monogyna), while more or less 
common in oak woods, are much more abundant in those of the 
